I bought some components, wasn't sure about how much of a power supply I needed - the build is as follows -
8GB Ram Gskill
EVGA GeForce GTS450
1TB Seagate Hard drive
Antec Truepower 550W 80 plus bronze
My concern is the video card... The guys at the store said 550 Watts was more than enough for this build. On the side of the video card box it says you need a minimum 400 W power supply with 22 amps on the 12 volt line. But the Antec Power supply says it has a max of 20 amps... So that isn't going to work is it? I haven't built it yet, kind of pisses me off if these guys reccomended a build that doesn't work... I had picked a 700W corsair power supply and they said it was way overkill for this build.
Will this PSU handle this video card or am I going to make big trouble for myself if I use it?
But it says right on the graphics card box: This graphics card requires: A 400 watt power supply or greater with a minimum 22 amps on the 12 volt rail.
This power supply says that it has +12V1, +12V2, +12V3, +12V4 - at 20 Amps each, maximum combined output 540 watts. So I've read that you can't just add up 20x4, you take the total watts divded by 12, which equals 45 here. So do you say the graphics card is ok because it has 45 amps, or does it need at least 22 amps on a single one of the +12V1, 2, 3, or 4 lines?
Video card manufacturers usually overstate the requirements because they don't know what type of psu a buyer has. They also don't know what the draw from other components is going to be.
The gpu needs only 9amps on a single 12v rail. And the 22amps also are referring to the entire system loads.
Ok thank you very much, I'm doing my first pc build here so I'm a little nervous about messing up, and that seems to be really the only part that seems intimidating - all the cables and power connections. But I'll just take my time and read the manual.
A reference clocked GeForce GTS 450 has a maximum graphics card power of 106 Watts. This means that the graphics card itself will draw up to a maximum of 8.8 Amps from the +12 Volt rails.
NVIDIA generally estimates 13 Amps from the +12 Volt rails to power the remaining devices in the system that require +12 Volt power such as the CPU, hard disk drives, CD/DVD drives, cooling fans, motherboard's chipset, etc. So 8.8 Amps for the video card plus 13 Amps for the remainder of the system gives 21.8 Amps which is rounded up to the recommended minimum 22 Amps on the +12 Volt rail.
The Antec True Power New TP-550 with its ability to produce up to 45 Amps on its combined +12 Volt rails is more than enough to power your system with a single GeForce GTS 450 graphics card. In fact there is enough +12 Volt current capacity to handle two GeForce GTS 450 graphics cards in 2-way SLI mode with overclocking if you so desire.